Questions tagged as 'mysql'

Tagged questions
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Why does THIS ERROR come out that I have an ambiguous field?

THIS IS THE INQUIRY: select asignaturas.materias, estudiantes.id_estudiantes, nombres,apellidos, calificaciones.id_calificaciones,n1,n2,promedio from asignaturas,estudiantes,calificaciones where id_calificaciones='$idcaliurl';     
asked by 04.02.2018 / 22:00
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Stored procedure to delete data in referenced tables

I need help with a stored procedure that allows me to delete a column in the usuarios table and when this column is deleted, delete all the data where it is used as primary key its id , the table that inherits from usuarios i...
asked by 07.02.2018 / 18:59
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How to add several records at once with php and javascript

I have knowledge in CRUD (Create, Read, Update and Delete) of MySQL PHP but in a last project of warehouse I wanted to make a form that the more inputs are requested, more rows of form can be added, but this I do not know how to add a id...
asked by 31.01.2018 / 03:24
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Change type of SQL query

I have a table that shows the results of mysql through a query, but I would like to be able to change the type of query. I leave you a simple example. $sql = 'SELECT * FROM avisos ORDER BY fecha DESC'; I need to use a button (or something s...
asked by 24.01.2018 / 12:47
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C # MySql Connection Error

I'm doing a project in C # but when I try to make the connection to the database it does not open and it generates the next error this is my code private void Form1_Load(object sender, EventArgs e) { try {...
asked by 23.01.2018 / 20:01
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Problems with database and array

I'm trying to do something as simple as a connection to a database and treat the data with an array, but there's no way I'm blocked. I'm getting an error I'm looking for, but there's no way. // control <?php include('../include/co...
asked by 24.01.2018 / 09:51
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validate existence before inserting

Hello good afternoon everyone, I previously asked this same question but I was recommended to open a new thread, I have to validate that before making an insert check if that record exists. If it exists, show me an alert message and ask me if I...
asked by 03.08.2018 / 17:21
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How to calculate arrears in mysql

hi friends I am trying to calculate the arrears of the teachers ... making the query I get what I want but reviewing the data I get in some fields with null values. Here the consultation: SELECT th.codigopersonal, tp.nombres, tr.fecha, th.dia,...
asked by 20.02.2018 / 16:59
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because I get it Warning: mysqli :: query (): Could not fetch mysqli in C: \ xampp \ htdocs \ test \ admin \ checklogin.php on line 8

<?php session_start(); $usuario=$_POST['username']; $contrasena=$_POST['password']; include("../library/config.php"); $ingreso = $conexion->query("SELECT * FROM administrador WHERE Usuario='$usuario' AND Clave='$contra...
asked by 02.03.2018 / 03:53
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How to unify three records from one table in another in MySQL?

I have a system that carries out a general inspection of the entire labor process on a daily basis, assigning certain values to it. Each inspection is formed by 3 stages, where each stage has its own set of values (3 records). The tables a...
asked by 01.03.2018 / 17:46